Email Forwarding/Relaying Rule

I want to make Zimbra working as "Mail Gateway" for our users and subsidiary companies' users.

What I'd like to do is;
1. Receive mail for multiple domains with zimbra. (I found how to do this part)

2. Forward mail to other mail server by domain. xxx@ABC.com mail needs to be forwarded to mail server: 10.10.10.10xxx@DEF.com mail needs to be forwarded to mail server: 20.20.20.20xxx@GHI.com mail needs to be forwarded to mail server: 30.30.30.30

I checked split domain documents but it does not seem the solution for me.

I can set up forwarding setting for each users one by one, but it take time if I do for 1000 users.

So I was wondering if there is a way to setup forwarding/relaying mail by domain?

Another question,
If we need to receive all email with Zimbra using @ABC.com domain, then forward/relay those emails to the other multiple mail servers within our organizations.
Is there a way to setup with Zimbra?